Papermaking machine



5 Sheets-Sheet 1 Filed Nov. 6, 1962 Aug. 10, 1965 c. T. BANKS PAPERMAKING MACHINE 5 Sheets-Sheet 2 Filed Nov. 6, 1962 C. T. BANKS Aug. 10, 1965 PAPERMAKING MACHINE 3 Sheets-Sheet 3 Filed Nov. 6, 1962 v United States Patent 'ice 3,199,449 PAPERMAKING MACHINE Charles '1. Banks, Neenah, Wis, assignor to Kimberly- (llark Corporation, Neenah, Wis, a corporation of Delaware Filed Nov. 6, 1962, Ser. No. 235,645 (Ilaims. (Cl. 100-153) My invention relates to papermaking machines and, more particularly, to compressing apparatus for stacks of thin material sheets, such as paper facial tissues.

It is an object of the present invention to provide an improved compressing apparatus capable of providing the necessary great forces on stacks of folded facial tissues to cause a substantial permanent reduction in height of such stacks, the compressing apparatus being relatively simple in design considering the high forces necessary for such height reduction.

It is a more particular object'in this connection to provide an improved compressing apparatus comprising pairs of opposed upper and lower rotatable drums arrange-d to have stacks of facial tissues pass between them with the drums being positioned so that the distances between successive pairs of the drums decrease whereby the stacks of paper are successively compressed to greater extents by the successive drum pairs. It is contemplated that endless belts may be provided around the upper and lower drums for carrying the stacks through the successively reduced dimension nips between the drums.

It has been found in connection with a compressing apparatus of this type that if it is used with relatively lightweight facial tissues, the uppermost tissues of a stack tends to adhere to the upper belt as the stack passes out from the last nip in the apparatus, thus disrupting the stack. This adherence of the top sheet of the stack apparently is due to static electricity generated by the compression of the stack.

It is a more particular object of the invention to provide means for preventing such disruption of the stacks passing through the apparatus, and it is contemplated in order to satisfy this object that the upper and lower belts may be made of electrically conducting material for causing the static charge to leak off the compressed tissue stacks. It is also contemplated that an auxiliary, relatively narrow, belt may be provided around the upper belt, with the arrangement being such that the narrow belt separates from the lower belt at the discharge end of the machine at a relatively small acute angle so that the narrow belt draws the uppermost tissue off the upper main belt.

The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above stated objects, and such other objects, as will be apparent from the following description of a preferred form of the invention, illustrated with reference to the accompanying drawings, wherein:

FIG. 1 is a side elevational view of compressing apparatus embodying the principles of the invention, the view being taken from one particular side of the apparatus;

FIG. 2 is a side elevational view of the compressing apparatus taken from the opposite side of the apparatus;

FIG. 3 is a plan view of the compressing apparatus;

3,199,44h Patented Aug. 10, 1965 FIG. 4 is a view on an enlarged scale of a pistoncylinder assembly in the compressing apparatus;

FIG. 5 is a side elevational view of a nip adjustment assembly in the compressing apparatus;

FIG. 6 is a view taken on line 66 of FIG. 5;

FIG. 7 is a side view of another nip adjusting assembly in the apparatus; and

FIG. 8 is a perspective view of a paper facial tissue stack which may be used in the compressing apparatus.

Like characters of reference designate like parts in the several views. 7

Referring now to the drawings and to FIG. 1 in particular, the illustrated compressing apparatus may be seen to comprise, in general, a framework 10, rotatable drums 11, 12, 13, 14, 15, and 16 on a lower level and drums 17,18, 19, 20, and 21 on an upper level, all supported by means of the framework 10.

The drums 11 to 21 each comprises a smooth outer cylindrical rim 22 and a central shaft 23 by means of which the drum is rotatably mounted. The drums 11 and 16 have their shafts 23 disposed in bearing blocks 24 which rest on shelves 25 formed by the framework 10. Adjusting screws 26' and 27 are provided for holding the bearing blocks 24 in suitably adjusted positions on the shelves 25.

Each of the drums 12 to 15 is mounted with respect to the framework It) by means of a pair of levers 28 located on opposite sides of each drum and pivotally connected to the framework by means of studs 29. A bearing block 30 is carried by each of the levers 28 for receiving one end of the shaft 23 of the associated drum, and an adjusting mechanism 31 is provided for adjustably fixing the other end of each of the levers 28 with respect to the framework 10. The mechanism 31 comprises a threaded stud 32 pivotally fixed at its upper end to the framework 10, a clevis 33 pivotally carried by the lever 28 and having the stud 32 extending through it, and adjusting nuts 34 on the stud end on opposite ends of the clevis.

An endless belt 35 of an electrically conducting material is disposed about the drums 11 to 16. The belt 35 may, for example, be stainless steel or saw steel about .040 inch thick'and may, for example, be about 7 inches Wide. A series of support rollers 36 carried by the frame work 10 are provided beneath the upper pass of the belt 35 between the drums 11 and 12, and a series of additional support rollers 37 carried by the framework 10 are provided beneath the upper pass of the belt 35 between the drums 15 and 16.

The drum 17 is supported with respect to the framework It) by means of bearing blocks 38 which receive the shaft 23 of the drum 17 and which are disposed on shelves 39 provided by the framework 10. Adjusting screws 40 and 41 carried by the framework 10 are provided for adjustably holding the bearing blocks 38 in suitable positions on the shelves 39.

Each of the drums 18 to 20 is supported by means of a pair of support levers 42 located on opposite sides of each drum. Each support lever 42 is pivotally mounted at 43 with respect to the framework 10 and comprises a sidewardly extending arm 44 and an upwardly extending arm 45 connected by means of a link portion 46.

Each lever 42, carries a journal block 47 for receiving one end of the shaft 23 of the associated drum.

A piston-cylinder assembly 48 (see FIGS. 1 and 4) is provided for applying a force on each of the levers 42 tending to rotate the lever downwardly about its pivotal connection 43. Each piston-cylinder assembly comprises a cylinder 49, a piston 59 slidably disposed in the cylinder and a piston rod 51 connected to the piston and to the end of the arm 44. The upper end of the cylinder 49 is connected to a fluid pressure conduit 52, and the lower end of the cylinder 4. 9 is swingahly mounted on a bracket 53 which is fixed with respect to the framework 10.

The lever 42 on one side of each of the drums l8, l9, and 29 has its movement controlled by means of an adjusting unit assembly 54-. Each assembly 54 (see FIG.

) comprises a frame 55 disposed on top of the framework ltl, a speed reducer 56, and a motor 57. The speed reducer 56 has an input drive pulley 5S and the motor 57 has a driven pulley 59; and a belt tit) is disposed about the pulleys 58 and 59 for driving the reducer 56 from the'motor 57. The reducer 56 has an output shaft 61 with a sprocket 62 fixed on it.

A screw 63 extends through the frame 55 and is held from longitudinal movement in one direction by means of a thrust bearing 64. A nut 65 is provided on the screw 63 and is in engagement with the associated lever 42, the screw 63 extending into an appropriate opening in the arm 45 of the lever 42. A sprocket 66 is fixed on the screw 63, and a drive chain 67 connects the sprockets 62 and 66.

The lever 42 on the other side of each of the drums 18, 19, and 20 has a similar assembly 54A for holding it in adjusted position. The assembly 54A is basically the same as each assembly 54 except that the motor 57 and the speed reducer 53 are not included, and the screw 63 in each assembly 54A is instead driven by means of a chain 68 (see FTG. 6) that extends over sprockets 69 and '78 fixed respectively on the screws 63 of the two opposite units 54 and 54A. An idler sprocket 71 is .provided for maintaining the chain 63 taut.

The drum 21 is mounted with respect to the framework 19 by means of levers 72 on opposite sides of the drum 21 and pivotally connected at 73 with respect to the framework lli. Each lever 72 carries a journal block of each lever 72, and adjusting unit assemblies MB and 54C corresponding generally to the assemblies 54 and 54A are provided for adjusting the levers 72 in position. The assembly 5413 comprises a motor 76 driving a speed reducer 77 which in turn drives a screw 78 having a nut 79 disposed on it and elfective on the arm portion 74. The speed reducer 77 drives the screw 78 through sprockets 3d and 81 and a chain 82. An idler sprocket 83 is provided for maintaining the chain taut. The assembly 54C comprises a screw 78 having a nut '79 on it, and the screw 78 of the assembly 540 is driven through sprockets 84 and 85 and a chain 86. An idler sprocket 87 functions to maintain the chain 36 taut.

An endless belt 38 of the same type as the belt 35 extends around the drums 17, 1d, 19, 2d, and 21. The drums l2 and 13, i3 and 19, 14 and 2d, and 15 and 21, respectively, are disposed one directly above the other with narrow gaps between them or more specifically between the belts 35 and 88 passing between the roll pairs. The gaps between the drums 12 and 13, 13 and 19, 14 and 2t and 15 and 21, successively decrease in order to compress the articles operated on by the apparatus as will be hereinafter described in greater detail. The drum 17 is disposed above the rollers 36, and there is a substantial gap between the rollers 36 and the drum 17 to provide an appreciable angle a between the belts 88 and 35 from the drum 17 to the drum 18 for purposes to be hereinafter described. The angle a may be approximately five degrees, for example, but may well be considerably larger, such as up to 30 degrees, for

'ing the pulley 122.

4% example. As will be apparent, the belts 35 and 88 may be maintained taut about the drums supporting the belts by adjusting the position of the drums Ill and 16 for the lower belt and by adjusting the position of the drum 17 for the upper belt.

A relatively narrow belt 89 also extends around the drums 17 to 21 in contact with the external surface of the belt 33. The belt 89 is held in spaced relation with respect to the belt 83 at opposite ends of the apparatus, a roller 9t adjacent the drum l7 and a roller $91 adjacent the drum 21 being provided for the belt 89 for this purpose. Each of the rollers 9th and 91 is rotatably mounted on the framework 110, and the roller fill is mounted so that the belt 89 makes a relatively small angle b with respect to the belt 35 in the portion of the belt 35 between the drum l5 and the rollers 37. The angle b is preferably small, about five degrees, for example, but may be larger, up to 30 degrees, for example. The belt 89, like the belts 35 and 88, may be of tempered steel, and it is considerably narrower than the belts 35 and 8S and may, for example, be about one inch wide. It is also preferably considerably thinner than the belts 35 and 8S and, if of steel, may be of about .005 inch thick.

The upper drums 13, 119, 29, and 21, and the lower drums 12, 13, 14, 15, and 16 are driven from a motor 2 for the purpose of moving the belts in a direction A. The motor 22 has a driving connection with a counter shaft 93 rotatably mounted with respect to the framework lt which includes a pulley Q4 on the motor 92, a pulley 95 fixed with respect to the counter shaft 93 and a belt 96 extending around the pulleys 94 and 95. A speed reducer 27 having a drive output sprocket 98 and an input drive pulley 9 is mounted with respect to the framework 149. A pulley ltiti is fixed to the shaft 93 and a belt Mill is disposed about the pulleys 99 and Mitt for driving the speed reducer 97 from the shaft 93.

The drum 12 is driven from the speed reducer W by means of a chain N2 that extends around the sprocket 98 and around a sprocket 193 which is fixed with respect to the shaft 23 for the drum 12. An idler sprocket 164 is provided for maintaining the chain 102 taut. It will be observed from FIG. 3 that all of the sprockets 98, 1%, and llil i are mounted on the outside of the framework lit).

The drum i3 is driven from the drum 12; the drum 14 is driven from the drum 13; the drum 15' is driven from the drum 14;.and, the drum in isdriven from the drum 15 by similar chain-sprocket drive combinations which include a chain 105, drive sprockets 1% and 167, and an idler sprocket 1.98 for driving the drum 13; a chain Hi9, drive sprockets lltl and 111 and an idler sprocket 112 for driving the drum 14; a chain 113, drive sprockets 114 and 115, and an idler sprocket lid for driving the drum l5; and a chain 117, drive sprockets 118 and 119, and an idler sprocket 12d for driving the drum 316. it will be noted that the chains m5, 199, 113, and 117 are all disposed within the framework it), but with the chains 165, m9, and 113 on one side of the drums and the chain 117cm the other side of the drums.

The upper drums l8, 19, 2d, and 21 are driven from a speed reducer 121 which is fixed with respect to the framework 1d. The reducer 121 has an input pulley 122, and a pulley 123 is fixed on the jack shaft 93, and a belt 124 extends over the pulleys 122 and 123 for driv- An idler pulley 125 is provided for maintaining the belt 124 taut. The reducer 1121 includes a fluid coupling 12-6 of conventional construction having a fluid tight housing with a bladed impeller 127 and a bladed runnner or driven element 12% disposed within the housing. The drive from the impeller 127 to the runner 123 is through the fluid within the fluid tight housing in accordance'with Well-known principles. The runner 128 has a driving connection through the re ducer 121, and the reducer includes an output drive sprocket 129. The sprocket 129 is drivingly connected to the drum 18 by means of a chain 1311 which extends over the sprocket 129, a sprocket 131 fixed with respect to the drum 18 and an idler sprocket 132 fixed with respect to the framework 19.

The drum 19 is driven from the drum 18; the drum 2% is driven from the drum 19, and the drum 21 is driven from the drum 213 by means of similar chain-sprocket drive combinations which include a chain 133, drive sprockets 134 and 135, and an idler sprocket 135 for driving the drum 19; a chain 137, drive sprockets 138 and 139, and an idler sprocket 141 for driving the drum 2%); and a chain 141, drive sprockets 142 and 143 and an idler sprocket 144 for driving the drum 21. The chain 13% and the sprockets 129 and 131 are on the outside of the framework 11) and the other chains 133, 137, and 141, together with the associated sprockets, are on the inside of the framework 10.

The compressing apparatus above described is particularly suitable for use for compressing articles of yieldable material having the form of a rectangular parallelepiped, the cross sections of which are rectangles. Such an article may be a stack 145 of interfolded facial tissues 146 (see FIG. 8) of creped tissue paper which stack is substantially compressible to reduced height.

In the operation of the compressing device, such an article 145 may be placed on the belt 35 at the intake end of the apparatus, which is its left end as seen in FIG. 1, on the exposed part of the belt 35, approximately beneath the roll 9%). The motor 92 drives the drum 12 through the belt 96, the pulleys 94 and 95, the jack shaft 93, the belt 101, the pulleys 1430 and 99, the reducer 97, the sprockets 93 and 153, and the chain 1G2. The drums 12, 13, 14, and 15 respectively drive the drums 13, 14, 15, and 16 through the chains 1115, 1139, 113, and 117, and the sprockets with which these respective chains are in mesh, so as to drive the belt 35 around the drums 11 to 16 and move the articles 145 on the belt 35 through the nips between the drums on the upper level and those on the lower level. At the same time, the motor 92 drives the drum 18 from the jack shaft 93 through pulleys 123 and 122, the belt 124, the fluid coupling 126, the reducer 121, the sprockets 129 and 131, and the chain 130. The drums 18, 19, and 211 respectively drive the drums 19, 2'3, and 21 through the chains 133, 137, and 141 and the sprockets in mesh with these respective chains so as to cause a corresponding movement of the upper belts 88 and 8). The sizes of the various pulleys and the gear ratios of the reducers 97 and 121 are such that upper belts are driven at the same linear speed as the lower belt 35. The fluid coupling 126, however, allows some minute ditferences of speed between the upper and lower belts so that in any case there is no creep, or minute differences in speed, or" the upper and lower belts with respect to each other.

' The distances between the upper drums 13, 19, 29, and 21, and the lower drums 12, 13, 14, and 15, respectively, successively decrease so that the upper belts and lower belt approach each other in the hips between the respective upper and lower drums. Thus, as the product 145 moves through the nips between the upper and lower rolls, it is progressively compressed to a greater and greater extent until it moves away from between the rolls 21 and 15 on to the exposed portion of the lower belt 35 at the discharge end of the machine adjacent the drum 15. The product 145 thus has been compressed substantially from its condition in which it is placed on the belt 35, and assuming that the product 14-5 is made up of folded creped facial tissues, it retains a permanent reduced height, so that the facial tissues as a stack may be packed in substantially thinner cartons than would otherwise be necessary.

Each stack of facial tissues may, for example, have a length of about 9% inches, a width of about 3% inches and a height prior to compression of about 3 to 3 /2 inches. After compression, the permanent reduced height of the stack may, for example, be about 2 or 2% inches so that the stack may easily be packed in a carton of 2 /2 inches height. The distances between the belts 88 and 35 in the four nips of the machine, namely, between the drums 18 and 12, the drums 19 and 13, the drums 2t and 14, and the drums 21 and 15, may respectively be approximately 1.37", .65, .60, and .58 for attaining this degree of compression. Such gaps provide pressures in the facial tissue stacks on the order of 1000 pounds per square inch at normal operating speeds of the belts which may, for example, be in the neighborhood of 260 feet per minute. 1

As has been previously described, the top sheet of a stack of folded tissues, apparently due to the static electricity generated by compression of the tissues, tends to stick to an upper belt in a compressor of the illustrated type, as the stacks leave the last nip in the compressor, thus disrupting the stack. Two expedients have been incorporated into the illustrated machine in order to remedy such difliculty. Firstly, both the upper and lower belts 88 and 35 have been made of an electrically conducting material, such as stainless steel or saw type steel, which results in some of the electric charge being drawn off the compressed facial tissue stacks. Other electrically conducting belts could also be used, such as cloth belts which have been metalized by spraying or cloth belts that have had metal strands woven through them. The second expedient is the provision of the narrow belt 82. As has been pointed out, the narrow belt 89 extends around the wide belt 83 and the narrow belt separates from the wide belt 35 at the outlet end of the machine by the small acute angle b which may be on the order of five degrees, for example, so that the narrow belt draws off any top tissues of the tissue stacks 145 from the upper belt 88 thus retaining the stacks complete. The top tissues of the stack do not adhere to the belt 89 since the belt 89 is quite narrow. The belt 89 although being disposed on the outer surface of the wide belt 83 does not form an appreciable groove in the compressed stack of tissues due to the fact that the belt 83 is very thin, having a thickness of only about .005 inch as has been previously mentioned.

It is of course, desirable to change the distances between the belts 88 and 35 in the hips between the upper and lower rolls in the event that different height stacks 145 of tissues are used in connection with the compressing apparatus. Each of the lower drums 12, 13, 14, and 15 may be adjusted vertically by releasing the nuts 34 and moving them vertically on the studs 32. The upper drums 18, 19, 20, and 21 are more easily adjustable with changed conditions by driving the respective motor 57 in one direction or the other. The output pulley 59 of the motor 57 if driven in one direction or the other drives the associated screw 63 in one direction or the other through the sprockets 62 and 66 and the chain 67, and the associated nut will thus move longitudinally along the screw 63 so as to cause the associated lever 42 to swing about its pivot 43 in one direction or the other. Fluid under pressure is applied continuously on the top surface of the piston 53 in each of the piston cylinder assemblies 48 so as to forcefully maintain the lever 42 bearing against the nut 65 on the screw 63 so that the lever follows the screw. The assemblies 54 and 54A operate to move the levers 42 on opposite sides of each of the top drums for the same distance due to the driving connection between the screws 63 of. the assemblies 54 and 54A through the sprockets 65 and and the chains 68. The assemblies 543 and 54C operate in substantially the same manner as the assemblies 54 and 54A to cause swinging movement of the levers 72 to change the distance between the drums 15 and 21. I

The illustrated compressing apparatus is particularly eifective in connection with stacks of very thin material sheets such as facial tissues which tend to become disrupted by the top sheet adhering to the uppermost belt 88, since the relatively narrow belt 89 overlying the relatively wide belt 88 functions to draw the upper sheet of the stack out of adherence with the upper belt 88. The machine is of simple design but yet has such rugged construction that it is capable of providing the high compressive forces necessary for giving a permanent set and reduced height to stacks of creped paper facial tissues which should have pressures in the neighborhood of 1000 pounds per square inch applied to them for this purpose. The compressing apparatus advantageously is constructed so that the distances between the upper and lower drums may be easily adjusted simply by energizing the motors 57 to drive in one direction or the other in order to change the compressive pressures or to adapt the machine for different height stacks of sheet material.

I wish it to be understood that the invention is not to be limited to the specific devices, constructions, and arrangements shown and described, except only insofar as the claims may be so limited, as it will be apparent to those skilled in the art that changes may be made without departing from the principles of the invention.

What is claimed is:

1. A machine for compressing stacks of folded thin sheet material comprising a plurality of rotatable drums which have parallel spaced axes of rotation, said drums being arranged in an upper series and in a lower series with each drum in the upper series having a relatively thin nip with a drum in the lower series, said nips decreasing in thickness from a first pair of said upper and lower drums in said series at an intake end of the machine to the last pair of said upper and lower drums in said series at a discharge end of the machine, a flexible belt of sheet steel disposed about the series of upper drums and a flexible belt of sheet steel disposed about the series of lower drums for carrying said stacks through said nips, means for rotating said drums so as to move said belts in a direction from the thickest nip to the thinnest nip for progressively compressing the stacks disposed between said belts, an auxiliary flexible belt of sheet steel of about .005 inch thickness which extends about said first named upper belt and which is narrower than said first named upper belt, and an auxiliary roll located adjacent to the last drum in said upper series for holding said auxiliary belt out of contact with said upper belt adjacent said last drum and for providing a relatively small angle between said narrow belt and said lower belt at the discharge end of the machine for holding the upper sheet of each stack of thin material from adhering to said first named upper belt.

2. A machine for compressing stacks of folded thin sheet material comprising a plurality of rotatable drums which have parallel spaced axes of rotation, said drums being arranged in an upper series and in a lower series with each drum in the upper series having a relatively thin nip with a drum in the lower series, said nips decreasing in thickness from .a first pair of said upper and lower drums in said series at an intake end of the machine to the last pair of said upper and lower drums in said series at a discharge end of the machine, a flexible belt disposed about the series of lower drums and a flexible belt disposed about the series of upper drums for carrying said stacks through said nips, means for ro'tatively driving said drums so as to move said belts in a direction from the thickest nip to the thinnest nip for progressively compressing the stacks disposed between said belts, said belts being of electrically conducting material tending to draw off the static electric charge caused by compressing said stacks, an auxiliary belt of electrically conducting material disposed about said upper belt and which is narrower than said uppermost belt, and a pair of auxiliary rolls for said auxiliary belt holding the auxiliary belt out of contact with said uppermost belt at opposite ends of said upper series of drums and providing a relatively small angle between said narrow belt and said lower belt at the discharge end of the machine for drawing off the uppermost sheet of each of said stacks of thin material from said first named upper belt.

3. A machine for compressing articles of yieldable material, comprising a stationary framework, a plurality of drums rotatably supported with respect to said framework to have parallel spaced axes of rotation, said drums being arranged in an upper series and in a lower series with each drum in the upper series having a relatively thin nip with a drum in the lower series, said nips decreasing in thickness from a first pair of said upper and lower drums to the last pair of said upper and lower drums in said series, a flexible belt disposed about the series of upper drums and a flexible belt disposed about the series of lower drums for carrying an article of yieldable material through said nips, a motor, driving means for connecting at least one of said upper drums with said motor for driving the upper drums, and driving means for connecting at least one of said lower drums with said motor for driving said lower drums, said two driving means being arranged to drive said two belts at substantially the same speed, one of said two last named driving means including a fluid coupling having a bladed impeller and a bladed runner or driven element, a housing within which the impeller and runner are disposed and fluid in the housing so that the bladed impeller drives the bladed runner through the fluid for permitting relatively small diflerences of movement between said upper and lower belts as said articles are being compressed.

4. A machine for compressing articles of yieldable material comprising a stationary framework, a plurality of rotatable drums, means for supporting said rotatable drums so that the drums have parallel spaced axes of rotation, said drums being arranged in an aligned upper series and in an aligned lower series with each drum in the upper series having a relatively thin nip with a drum in the lower series, said nips decreasing in thickness from a first pair of said upper and lower drums to the last pair of said upper and lower drums in said series, said supporting means for one of the drums of each drum pair comprising a pair of levers swingably mounted on said framework and carrying journals for opposite ends of the drum, a motor effective on each of said levers for applying a constant force on the lever tended to swing it in the direction to move the drum carried by the lever toward the drum nipped therewith, a movable stop eflective on each of said levers for preventing movement of the lever in the direction in which the said motor effective on the lever tends to move the lever but allowing movement of the lever in the opposite direction against the action of the motor, and means for simultaneously adjustably moving the stops for the two levers of each of said pairs of levers so that the two levers of each of said pairs of levers are in substantially the same rotative positions.

5. A machine or compressing stacks of folded thin sheet material comprising a plurality of rotatable drums which have parallel spaced axes of rotation, said drums being arranged in an upper series and in a lower series with each drum in the upper series having a relatively thin nip with a drum in the lower series, said nips decreasing in thickness from a first pair of said upper and lower drums in said series at an intake end of the machine to the last pair of said upper and lower drums in said series at a discharge end of the machine, a flexible belt disposed about the series of upper drums and a flexible belt disposed about the series of lower drums for carrying said stacks through said nips, means for rotating said drums so as to move said belts in a direction from the thickest nip to the thinnest nip for progressively compressing the stacks disposed between said belts, an auxiliary flexible belt which extends about said first named upper belt, and an auxiliary roll located adjacent to the last drum in said upper series for holding said auxiliary belt out of contact with said upper belt adjacent said last drum and for providing a relatively small angle between said auxiliary belt and said lower belt at the discharge end of the machine for holding the upper sheet of each stack of thin material from adhering to said first named upper belt, said two first named flexible belts being made of electrically conducting sheet material and said auxiliary belt also being made of electrically conducting sheet material and being substantially narrower and substantially thinner than said two first named belts.

References Cited by the Examiner UNITED STATES PATENTS 321,039 6/85 Lehman 100-1l8 X 603,945 5/98 Edgerton l00-153 X 631,567 8/99 Fowler 100154 X 780,145 1/05 Vaughan 198184 1,007,519 10/11 Blain et a1. 100154 1,179,737 4/16 Manly 100-162 1,430,166 9/22 Hinckley 100174 10 10/22 Taggart 100154 X 5/31 Upson et al 100118 X 1/35 Winter et al 100154 X 8/51 Faller 198-185 X 10/55 Hessler et .al. 144-2812 10/59 Off-utt et a1 198165 11/60 Greiner et a1. 100152 FOREIGN PATENTS 7/51 Germany.

WALTER A. SCHEEL, Primary Examiner.

LOUIS O. MAASSEL, Examiner. 

1. A MACHINE FOR COMPRESSING STACKS OF FOLDED THIN SHEET MATERIAL COMPRISING A PLURALITY OF ROTATABLE DRUMS WHICH HAVE PARALLEL SPACED AXES OF ROTATION, SAID DRUMS BEING ARRANGED IN AN UPPER SERIES AND IN A LOWER SERIES WITH EACH DRUM IN THE UPPER SERIES HAVING A RELATIVELY THIN NIP WITH A DRUM IN THE LOWER SERIES, SAID NIPS DECREASING IN THICKNESS FROM A FIRST PAIR OF SAID UPPER AND LOWER DRUMS IN SAID SERIES AT AN INTAKE END OF THE MACHINE TO THE LAST PAIR OF SAID UPPER AND LOWER DRUMS IN SAID SERIES AT A DISCHARGE END OF THE MACHINE, A FLEXIBLE BELT OF THE SHEET STEEL DISPOSED ABOUT THE SERIES OF UPPER DRUMS AND A FLEXIBLE BELT OF SHEET STEEL DISPOSED ABOUT THE SERIES OF LOWER DRUMS FOR CARRYING SAID STACKS THROUGH SAID NIPS, MEANS FOR ROTATING SAID DRUMS SO AS TO MOVE SAID BELTS INA DIRECTION FROM THE THICKEST NIP TO THE THINNEST NIP FOR PROGRSSIVELY COMPRESSING THE STACKS DISPOSED BETWEEN SAID BELTS, AN AUXILIARY FLEXIBLE BELT OF SHEET STEEL OF ABOUT .005 INCH THICKNESS WHICH EXTENDS ABOUT SAID FIRST NAMED UPPER BELT AND WHICH IS NARROWER THAN SAID FIRST NAMED UPPER BELT SAID UPPER SERIES FOR HOLDING SAID AUXILIARY BELT OUT OF SAID UPPER SERIES FOR HOLDING SAID AUXILIARY BELT OUT OF CONTACT WITH SAID UPPER BELT ADJACENT SAID LAST DRUM AND FOR PROVIDING A RELATIVELY SMALL ANGLE BETWEEN SAID NARROW BELT AND SAID LOWER BELT AT THE DISCHARGE END OF THE MACHINE FOR HOLDING THE UPPER SHEET OF EACH STACK OF THIN MATERIAL FROM ADHERING TO SAID FIRST NAMED UPPER BELT. 